Scholars recognize William H. Durham as responsible for introducing a non-Wesleyan theology of sanctification into the early pentecostal movement. Because the controversy over Durham's "finished work of Calvary" theology precipitated a rift in early Pentecostalism that had lasting institutional ramifications, Durham occupies a crucial place in pentecostal historiography. Yet, scholarly treatment of Durham has been hindered by misjudgments in three areas of inquiry. First, a series of unsupported historical details has led to a dubious timeline for the unveiling of the finished-work teaching. Second, the chronological errors have obscured the role of A.S. Copley in the early stages of pentecostal anti-Wesleyan theology. Third, a Durham-centered interpretation of the origins of Oneness Pentecostalism has distorted Durham's basic soteriological insights. Scholars recognize William H. Durham as responsible for introducing a non-Wesleyan theology of sanctification into the early pentecostal movement. Because the controversy over Durham's "finished work of Calvary" theology precipitated a rift in early Pentecostalism that had lasting institutional ramifications, Durham occupies a crucial place in pentecostal historiography. Yet, scholarly treatment of Durham has been hindered by misjudgments in three areas of inquiry. First, a series of unsupported historical details has led to a dubious timeline for the unveiling of the finished-work teaching. Second, the chronological errors have obscured the role of A.S. Copley in the early stages of pentecostal anti-Wesleyan theology. Third, a Durham-centered interpretation of the origins of Oneness Pentecostalism has distorted Durham's basic soteriological insights.